Retort



United States Patent References Cited UNITED STATES PATENTS Davis Assistant Examiner-Leon G. Machlin Altorney- Parmelee, Utzler & Welsh ABSTRACT: A retort for sterilizing food products in sealed cans or jars. There is an outer cylindrical shell in which is an elongated rotatable cage suspended for axial rotation by a flexible chain loop at each end of the cage. The chain at one end is a drive chain passing around a sprocket wheel and over a power-driven drive sprocket within a sealed enclosure at the top ofthe shell, and the chain at the other end is looped under the cage and over an idler sprocket, also in a sealed enclosure on the top of the shell. Baskets loaded with the food containers are rolled into and out of the retort through a door at one end of the shell and along tracks positioned on opposite sides of the cage. The containers are confined in the baskets when the cage is rotated to agitate the contents of the container during heating and subsequent cooling. Provision is made for retaining an effective level of cooling water in the shell for cooling the containers after sterilization.

Patented Oct. 6, 1970 Sheet Attornys.

Patented Oct. 6, 1970 Sheet Q R l/UQ\ I. k

Patented Oct. 6, 1970 Sheet 3 of3 m Qmw Ms M 2m w, m T-L. mm r fl m 6 M B 3 Attorneys.

RETORT This invention is for a retort for use in sterilizing previously canned food product, and particularly to a retort in which the cans are confined in a rotating cage whereby they are constantly moving through a circle from an upright to an inverted position and back to agitate the contents of the cans and more quickly heat the contents than in retorts in which the cans are stationary.

Sterilizing retorts of this general type have heretofore been successfully used. In general they comprise a horizontal cylindrical drum with a loading door at one end. Inside the drum there is a cage, and baskets, loaded with cans, are moved endwise through the door into the cage. After sealing the door, the retort is filled with steam and a predetermined pressure is maintained while the cage is rotated, continuously turning the baskets from an upright to an inverted position and back to an upright position, thereby agitating the contents of the cans to accelerate the difi'usion of heat into the contents and possibly prevent the contents from burning onto the interior of the cans.

The cage in such prior structures rests on rollers at each side of the bottom of the drum or retort, and at each end of the cage, and these rollers project through openings in walls of the retort. These rollers are carried in bearings provided in external housings that cover the openings in the retort so as to prevent the escape of steam. The cage is driven by an axiallyextending shaft at the end of the cage most remote from the door. This shaft passes through a gland on the end wall of the retort opposite the door, and a motor drive at the outside of said end wall is operatively engaged with the shaft. The entire construction was costly, the rollers and bearings were constantly immersed in water from condensed steam, except when it evaporated during sterilizing of the cans, and if the cage did not turn on a true circle, the drive shaft and packing gland through which it passed was stressed, resulting in leakage and need for repair.

The present invention has for its object to provide an improved and less costly construction. This is accomplished wherein the loading end of the cage is suspended in a chain loop passing over an idle sprocket in an enclosure at the top of the retort. At the other end of the cage there is a stub shaft on which is a sprocket wheel, and a drive chain engaging the sprocket wheel and a drive sprocket, also within an enclosure at the top of the shell, rotatably supports and drives the cage. The baskets, instead of being on caster wheels, have rollers at the sides that ride on rails at opposite sides of the cage, so that the usual track arrangement inside the cage is not required. A vertically-adjustable bottom bar under the baskets holds them tight against a cover plate inside the cage. A weir arrangement in the retort provides for a pool of constantly changing water to be maintained in the retort through which the baskets rotate to cool the cans before the retort is opened.

These and other objects and advantages are secured by the invention as hereinafter more fully described in connection with the accompanying drawings showing a preferred embodiment of the invention, and in which:

FIG. I is a perspective view of the retort with parts broken away to show the interior;

FIG. 2 is a longitudinal vertical section through the retort;

FIG. 3 is a transverse vertical section in the plane of line III-III of FIG. 2;

FIG. 4 is a fragmentary side elevation of the vertically-adjustable bottom bar in the cage;

FIG. 5 is a fragmentary perspective view of the idle sprocket assembly at the top of the retort; and

FIG. 6 shows one of the baskets, loaded with cans, partly in side elevation and partly in section.

In the drawings, in which like reference numerals designate like parts, 2 designates the cylindrical body of the retort which is formed of plate metal. It is supported on a foundation (not shown) by two structural steel cradles 3. At one end there is the usual door 4, which can be sealed against the end of the retort 2 against relatively high internal pressure. This door is of usual construction. and the hinge and locking hardware commonly provided in such doors is not shown. At the opposite end of the retort, herein termed the rear end, while the door end is the front end, there is a rear end wall 5 having a central flanged manhole 6 to provide access to the interior of the retort through its rear end for maintenance or servicing of this end of the retort.

For a short distance inside the front end, there is an entrance portion 7 of a length slightly greater than the length of one of the baskets (to be hereinafter described) and inside this entrance portion are diametrically-opposed side rails 8 in the form of angles secured to the interior of the retort with the tops of the angles at about the transverse horizontal center line of the retort.

Back from the entrance portion 7 there is a longitudinallyextending cage designated generally as 9 having a front ring portion 10 and a rear ring portion 11. Extending between these are various structural members 12 carrying the two rings together into a generally cylindrical open cage. The forward end of the cage within the inner diameter of the ring 10 is open as indicated at 10a. The rear end of the cage has two diametrically-opposite extending structural members at right angles to each other designated 13 and 14. These members form a rigid end structure, and at the axis of the cage which is at the juncture of these members, there is a shaft 15. This shaft is loosely received in a stabilizer box 16 inside the retort-adjacent the rear wall 5, the stabilizer box 16 being carried on a structural cross member 17 that is welded at its opposite ends to the side wall of the retort. The stabilizer box 16 does not support the rear end of the cage 9, but merely serves to stabilize wobble of the cage as it begins to rotate. The support for the rear end of the cage 9 will be described hereinafter in conjunction with the drive means for the cage 9.

The ring 10 at the front has a peripheral groove 18 therein. Located on the top of the shell 2 of the retort above the ring 10 is a first sealed enclosure 19 fixed on and opening into the interior of the shell. There is an idler shaft 20 extending through this enclosure above the axis of the cage, and there are packing glands 21 on each side wall of the enclosure where the shaft passes therethrough. The shaft is supported in bearings 22 mounted on the top of the retort and exteriorly of the enclosure. The shaft 20 has a sprocket wheel 23 secured thereto and a sprocket chain 24 passes over the wheel 23 which is an idler wheel, downwardly through pipes 25 that are sealed into the enclosure and into the interior of the retort, the chain looping under the ring 10 in the groove 18, thereby providing a support for rotatably holding the front end of the cage centered inside the shell. This provides an endless traveling flexible sling for the front end of the cage, while the loadcarrying bearings for the shaft 20 are entirely outside the atmosphere in the retort.

As best seen in FIGS. 2 and 3 the cage is provided with a flat plate or panel 30 which extends throughout the length of the cage, and which is welded at its opposite ends to the rings 10 and I1. When the cage is in a position for the reception of the baskets of cans, or for removal of the baskets of the cans from the retort, the plate 30 is in the position shown in FIG. 3 at the top of the cage. At diametrically-opposite sides there are rails 31, which form a trackway along which the baskets are moved in the manner to be hereinafter described, the tops of these rails 31 being substantially in the plane of the horizontal diameter when the parts are in the position shown in FIG. 3.

Diametrically opposite the panel 30 there is a bottom supporting bar extending lengthwise of the cage, and the details of which are best seen in FIG. 4. This bar, designated 32, has inclined surfaces 33 on the under face thereof, and these engage oppositely-inclined surfaces 34 on a supporting bar 35 which is under the bar 32. Secured to the front of the ring I0 there is a bracket 36. A screw shaft or adjusting bolt 37 passes through this bracket and is threaded into the end of the lower bar 35. It is provided with a fixed thrust collar 38 that bears against the inner face of the bracket 36 while the outer end of the bolt has a hex head 39 or other means by which the bolt may be readily turned. By turning the bolt 39 in one direction to move the lower bar 35 toward the left as viewed in FIG. 4, the bottom supporting bar 32 will be adjustably raised, while turning the bolt 37 in the opposite direction will allow the bottom supporting bar 32 to lower.

It will be noted in FIG. 2 that when the cage is in the position so that the panel 30 is at the top, the rails 31 in the cage will be in exact alignment with the rails 8 in the entry portion of the retort.

The so-called baskets which are shown in FIG. 6 are designated generally as 40, and they are all of like construction. They are formed of spaced slats or strips, and they are generally square in transverse section and nearly cubical in shape. The cans, designated 41, are arranged in rows and layers in the baskets. Generally the baskets are proportioned to the needs of the cans which are to be processed, and in the particular instance shown, there are five layers of cans separated from the one below by a perforated removable plate 42. The strips forming the sides of the can-retaining receptacles or baskets are designated 43 in FIG. 6. On each side of each can-retaining receptacle or basket there is a strip 44, and there are two rollers 45 on each of these horizontal strips 44. At the forward end of each basket or receptacle there is a pivoted latch member 46 adapted to hook over a pin 47 on the basket or retainer ahead of it when two such containers are pushed together.

There is indicated in the drawings a valved cold water inlet pipe at the side of the retort at 50. Preferably there would be a plurality of these cold water inlet pipes arranged along the length of the shell, and at 51 there is a weir extending up from the bottom of the retort adjacent the rear end of the cage. There is a valvecontrolled drainage pipe 52 in the bottom of the retort to the rear of this weir, and there may be another valved drainage pipe 53 in the bottom of the retort forwardly of the weir.

There is a sprocket wheel 54 on the shaft at the rear of the cage. A drive chain 55 passes around this sprocket wheel and up through an opening 56 in the top of the retort over a drive sprocket wheel 57 that is located in a second sealed enclosure 58 at the top of the retort fixed on and opening into the interior of the retort. It is above the shaft 15 and the sprocket wheel 54. The sprocket wheel 57 is fast on a shaft 60 that passes through the enclosure 58 through sealing glands 59, and the ends of the shaft 60 are supported in bearings 61 entirely outside the enclosure. The endless drive chain so arranged provides a flexible traveling sling for rotatably suspending the rear end of the cage in a manner similar to the suspension for the front end, as well as serving to rotate the cage when drive sprocket 54 is rotated. One end of the shaft 60 passes through the bearings 61 and has a sprocket wheel 62 thereon. A chain outside the shell transmits motion from a sprocket wheel 64 to the sprocket wheel 62, the motor and speed-reducing gear for the sprocket 64 being schematically indicated at 65.

It will thus be seen that the cage is rotatably suspended inside the shell, while the shafts from which the chains are hung at the top of the shell are carried in bearings outside the shell, and these hearings are free of any stresses tending to misalign them due to irregularity in the loading of the drum, such as results in conventional structures where there is an axial drive shaft passing through the casing at one end of the cage.

In the operation, with the retort empty and the door 4 swung to a full open position, a forklift truck may raise the loaded basket to a level where the rollers 45 will engage the rails 8 in the entry portion of the retort, and the loaded basket then pushed forward on these rails, and on into the cage. A succeeding basket is similarly loaded into the retort and pushed toward the rear, and this is continued until all of the baskets together fill the length of the cage, and as the baskets are pushed in and eventually the innermost one reaches the end of the cage, the latches 46 engage over the pins 47 of the basket ahead and they are all coupled together. When the cage has been loaded in this manner, the bolt 37 is turned to move the wedge bar 35 to the left as viewed in FIG. 4, raising the bottom support bar 32 to lift the baskets or can-holding receptacles upwardly so that the tops of these receptacles are tight against the perforated panel 30. The baskets cannot then move, and the cans in the open top of the baskets are confined against the perforated panel 30, and thus all of the cans are confined in the basket against any substantial relative movement.

After the cage has been loaded, the door 4 is sealed shut and steam is admitted to the retort through a steam pipe at the front end of the retort. The steam may also pass up into the enclosures 20 and 58, but any condensation which forms in these areas can drain directly back into the retort. With the admission of steam the cage is rotated by operation of the motor 65 and the baskets of cans are thus constantly moved from an upright to an inverted position and back to an upright position, thereby agitating the more or less liquid contents of the can to accelerate the diffusion of heat into the product within the can and prevent possible scorching of the product onto the sides of the cans and effect more uniform heating of the contents. If the cage is of an open structure and the top panel 30 is perforated, and the baskets or can containers are of a slatted crate-like construction. steam has ready access to the cans, and this access is increased by the fact that the separator plates 42 between the layers olcans are also perforated.

After the cans have sterilized for the required period of time at the required temperature, the steam supply may be cut off, and to accelerate cooling, water may be introduced into the retort through the pipe 50. It will collect in a pool between the door end of the retort and the weir 51 until such time as it overflows the weir. At this time the drain pipe 52 may be opened and incoming cold water may replenish the water in the pool while the heated water flows over the weir. The continued rotation of the cage clips the baskets down into this water and then lifts the water up with the rotation of the cage to cascade down through the cans, thus enabling them to be more quickly cooled to a temperature where they can be removed from the retort. When this condition has been reached, the drain pipe 53 may be opened and the water supply 50 closed and the retort completely drained, after which the door 4 can be opened. The bolt 37 is then turned in the opposite direction to drop the bottom support bar 32, whereupon the string of baskets or can-holding receptacles now, all hitched together, can be pulled forward, and each basket in turn released from the one behind it and removed with a fork-lift truck.

As indicated above, all bearings are in the atmosphere where they can be oiled, and where they are not exposed to the steam and water. The use of the flexible element or chain 24 with the sprocket wheel 23 on the shaft 20 and the drive and supporting chain at the rear of the cage allows the cage to freely rotate, and keeps it centered without the need of rollers such as heretofore have been required with the attendant drawbacks to these rollers. The stabilizer box 16 at the rear of the cage does not have to be packed so that there is no possibility of a packing leaking due to possible slight eccentric movement or wobble of the shaft. Since the baskets are supported at the sides, they can be handled on a fork-lift truck, and space heretofore required for baskets with casters and a trackway in the bottom of the cage such as heretofore has been necessary, is no longer needed.

While we have shown and described one specific embodiment of our invention, it will be understood that various changes and modifications may be made therein within the contemplation of the invention and under the scope of the following claims.

We claim:

I. A retort comprising a horizontally-elongated cylindrical shell having a rear wall at one end and a door for closing the other end, said shell having:

a. a horizontally-elongated rotatable basket-receiving cage therein, the forward end of the cage confronting the door and being open to receive baskets loaded with cans therethrough, the rear end of the cage having a shaft extending toward and terminating forwardly of the rear 5 wall;

b. an endless chain looped under the forward end of the cage for supporting the forward end;

c. a steam-tight enclosure on the shell over the forward end of the cage having an idler wheel rotatably supported therein over which said chain passes for suspending the forward end of the cage;

. a second steam-tight enclosure on the shell over said shaft having a drive sprocket therein;

e. the shaft having a sprocket thereon under said drive sprocket, with a chain engaging both sprockets for rotatably supporting the rear end of the cage; and a driving mechanism outside said second enclosure connected with the drive shaft whereby the cage may be rotated within the shell.

. A retort comprising:

an elongated horizontal shell having a door at its front end and a rear end wall;

. a rotatable cage inside the shell open at its forward end and having a shaft extending axially from the rear end thereof;

the cage having a ring thereabout near its forward end;

. a first enclosure on top of the shell above the ring on the cage;

an idler shaft passing through the first enclosure and mounted for rotation in bearings at the exterior of the first enclosure;

the idler shaft having an idler wheel thereon within the first enclosure;

. an endless chain passing around the idler wheel and under the ring on the cage for rotatably supporting the forward end of the cage;

. a second enclosure on the top of the shell above the shaft on the cage;

. a drive shaft passing through the second enclosure and mounted for rotation in bearings at the exterior of the second enclosure;

j. means externally of the second enclosure for driving the drive shaft;

. means on the drive shaft within the second enclosure extending into the shell for supporting the shaft on the cage and for transmitting rotary motion from the drive shaft to the shaft on the cage; and

. means within the cage providing a track along which canretaining receptacles may be supported by and moved into and out of the cage.

3. A retort as defined in claim 2 wherein the first and second enclosures include packing glands where their respective shafts pass therethrough.

4. A retort as defined in claim 2 wherein the endless chain passes through pipes that are sealed into the first enclosure and into the interior of the shell.

5. A retort as defined in claim 2 including:

a. a weir extending upwardly from the bottom of the shell adjacent the rear end of the cage;

b. a valved cold water inlet pipe at the side of the shell forwardly of the weir; and

c. a first valved drainage pipe in the bottom of the shell to the rear of the weir, the arrangement being such that cold water may be introduced into the shell through the cold water inlet pipe and allowed to collect in a pool through which the cage revolves between the door and the weir until such time as it overflows the weir and discharges through the first drainage pipe.

6. A retort as defined in claim 5 including a second valved door and the weir when the door is to be o ened.

7. A retort as defined in claim 2m WhlC the cage has a canretaining panel at the top when the cage is rotated to a position where the can-retaining receptacles may be moved into the open end of the retort and cage for retaining cans in the receptacles positioned on the track when the cage rotates.

8. A retort as defined in claim 7 in which the cage has a bar diametrically opposite the panel arranged to be adjusted toward and away from the panel to clamp the tops of the canretaining receptacles against the panel.

9. A retort as defined in claim 8 in which the can-retaining receptacles are box-like perforated baskets with open tops and which have rollers at each side thereoflthe track means comprising rails extending along the interior of the cage at diametrically opposite positions between said panel and said bar, the rollers at the sides of the baskets being at a level to rest on and roll on said rails.

10. A retort as defined in claim 9 in which there is an entrance section between the door and the open end of the cage in which there are rails that align with the rails in the cage when the cage is turned to a position to receive and discharge baskets.

11. A retort as defined in claim 9 in which the baskets have cooperating coupling means at the ends thereof for automatically releasably coupling one basket to another when they are pushed together in end-to-end relation, whereby the baskets may be individually pushed into the cage and each coupled to the one preceding it such that the baskets may be pulled out of the cage in a connected series and disconnected one at a time as they reach the door.

12. A retort for sterilizing food products comprising:

a. a horizontally-elongated cylindrical shell having a door at its forward end and which is closed at the rear end in which an atmosphere of steam under pressure may be maintained when the door is closed;

b. a horizontally-elongated rotatable basket-receiving cage within the shell, the forward end of which is open for the entrance and removal of container-holding baskets to be confined in the cage during sterilization;

c. means at the front and rearends of the cage providing endless traveling slings for rotatably suspending the cage within the shell including a pressure-tight enclosure means on the shell for portions of said last-named means, the interior of said enclosure means being exposed to steam pressure in the shell;

d. driving means outside the shell and the enclosure for transmitting motion to one of said endless traveling slings for rotating the cage; and

e. means for supplying steam to the interior of the shell.

13. A retort for sterilizing food products as defined in claim 12 wherein said means at the front and rear ends of the cage providing endless traveling slings comprises a pair of flexible chains, one of which is suspended from an idler sprocket within a pressure-tight, enclosure on the top of the shell with its interior opening into the interior of the shell, and the other of which is a drive chain suspended from a drive sprocket within a pressure-tight enclosure on the shell with its interior opening into the interior of the shell, the cage having a sprocket wheel afiixed thereto'about which the drive chain is engaged.

14. A retort as defined in claim 13 wherein the cage has a stub shaft at the rear end thereof on which the sprocket wheel on the cage is fixed, and confining means within the shell in which the free end of the stub shaft is loosely received for restricting the wobble of the rear end of the cage when the to support the shell. 

